help with some math

[scouty]

Hi all, I'm a little embarrassed, I need to go back to the 1st grade and start over. I've been loading 115g RN Rainier bullets with 4.5 g of titegroup. Have not had any problems shooting these rounds. I've been reading on here how these bullets should be treated like cast bullets and the charge reduced by 10%. Would someone please tell me how much the charge should be. Does anyone have a formula they use for reducing loads. I realize 10% is not going to reduce these by much, but I'm just not sure how to figure this. It would be easy to blame the public school system but this is my fault I really feel DUMB!!! Also got my load info from my Lee manual. Thanks all and hope everyone had a MERRY CHRISTMAS

[DiscoRacing]

ten percent of 4.0 would be .4... which is four tenths... so you could use 4.1 instead of 4.5

[scouty]

Thanks DiscoRacing, That makes sense.

[DiscoRacing]

Ya welcome Friend.... Happy Holidays...

.... not first grade...

... all they do is color
... no decimals till third grade...J/K

[Qtiphky]

Scouty,
I missed those posts saying to reduce by 10%. I have been loading Rainiers for several years now at the normal published levels and haven't had any problems. Granted I'm nowhere near max, closer to low/middle loads, so it shouldn't be a problem. However?

Why would you need to reduce the loads by 10%? They are jacketed bullets, not cast, correct? Hope I haven't been doing something wrong all this time and just been lucky. I've got well over 2,000 shot and probably another 1,000 sitting in the que to be shot.

[DiscoRacing]

Hope I haven't been doing something wrong

Dont worry Qtip...

... no harm done.
.

Ive NEVER reduced by any percent..

...and I wish I had a counter on my press to see just how many thousand rds I didnt reduce on.

[scouty]

Qtiphky, I've seen several posts on here about this, and Rainiers website says it also. I guess there might be an issue with the jacketing coming off at higher loads. Not sure on this. I agree with you, I haven't had any problems with my loads taken from the manual. The Lee manual does list cast bullet loads, just not for 115 RN.

[DiscoRacing]

this is directly from Hodgen site loading manual for Titegroup powder

115 GR. LRN Hodgdon Titegroup .356" 1.100" 3.9 1075 25,800 CUP 4.3 1151 30,500 CUP

it says 3.9 grains to 4.3 grains.

I load all my 9mm at 4.0... because I only shoot them at paper anyway.

[Qtiphky]

Lee has a real basic program for tracking your rounds. It also tracks all of your firearms and this could be helpful in an insurance claim or if one gets stolen. It is called Lee Shooter.

Or, you can log all of your loads in a spreadsheet. I am far from OCD, but I am a data collector and use both. The spreadsheet works better for side by side comparison of group sizes, velocity, where they hit in regards to bull before sighting in, things like that. The Lee program works for tracking just about everything else. You can enter notes in the Lee program to tell you the same data, but I like numbers as opposed to reading in paragraph form in a report.

[scouty]

It's really surprising the span between acceptable loads on the same bullet. 3.9 from Hodgdon to 4.5 and thats low end in the Lee manual. Using titegroup

[DiscoRacing]

see if this link works for the site.. .you can look for yourself

http://data.hodgdon.com/cartridge_load.asp

just click on the tab for pistol load..and for 9mm

[jbrown13]

[QUOTE]Lee has a real basic program for tracking your rounds. It also tracks all of your firearms and this could be helpful in an insurance claim or if one gets stolen. It is called Lee Shooter.[QUOTE]

Lee Shooter will not work with Windows 7 for some reason. It will not handle the data you input, and the data is lost when you try to recall it. When I upgraded from XP I contacted Lee about the problem. They were not inclined to modify the Lee Shooter program to run on Windows 7. My guess is it may not work with Windows Vista since it is a similar platform Windows 7. I guess Lee does not consider it a money maker, so they are letting it die.

[CrustyFN]

I have always loaded Berry's and Rainier with jacketed data, Berry's recommends jacketed data for their bullets. To me 4.5 grains of TG sounds a little on the warm side. I load 4.2 grains when I use TG but I found a powder I like better and don't use much TG any more.

[BarbreJ]

Not that is matters anymore since most use jacketed data, but to find 10% you just multiply by 0.9.

4.5gr x 0.9 = 4.05gr

[Unclenick]

Qtifky and Scouty,

The plated bullets are not jacketed bullets. Jacketed bullets have jackets formed from gilding metal which is 95% copper and 5% zinc. Though copper-colored, it is actually a form of mild brass. The copper plated bullets have a pure copper plating which is softer than gilding metal. Most plated bullets are closer to cast bullet hardness than to jacketed bullet hardness.

The problem this causes is that soft bullets are upset more by pressure so they can pack a gun's chamber throat. This means that at low pressure they're softness makes them easier to push into the rifling throat, but high pressure distorts them more than a jacketed bullet, making them harder to push in. In other words, with maximum jacketed bullet loads, the same charge can produce higher chamber pressure with a soft bullet than the same-weight and shape jacketed bullet will do. That's the reason for lowering a maximum jacketed load by 10% for plated bullets as an estimate.

This problem will not occur in equal amounts with all brands, as even the pure copper is harder than lead, but it has to be pretty thick to catch up with jacketed bullet hardness. It also varies with peak pressures in the cartridge and also varies with the gun's chamber shape. You almost have to have pressure measuring gear on your particular gun to find loads that match jacketed bullet load peak pressures closely. The 10% powder reduction reduces pressure around 20%, and that's done as a rule of thumb for a safety margin.

[scouty]

Thanks BarbreJ ans Unclenick , two informative posts

[orionengnr]

UncleNick--
As always, good stuff. I had wondered about that, and my guess would have been that lead has less friction than a copper jacketed bullet, and therefore requires less powder to acheive a similar velocity.

I wasn't totally wrong, but what I had right was mostly for the wrong reason Thanks for the clearly written, informative post.

[Don P]

It's really surprising the span between acceptable loads on the same bullet. 3.9 from Hodgdon to 4.5 and thats low end in the Lee manual. Using titegroup

Its called CYA (cover your ass ) Everyone is doing there best to see that we re loaders don't hurt ourselves. You know the old adage give them an inch and they'll take a foot. I load my 9mm 125 grain cast lead over 3.8 grains of Titegroup.